gh-125875: Fix docs typo FORMAT_SPEC to FORMAT_WITH_SPEC (gh-126319)

Fix docs typo FORMAT_SPEC to FORMAT_WITH_SPEC
(cherry picked from commit 914356f)

Co-authored-by: rimchoi <[email protected]>

Author: rimi0108

Doc/library/dis.rst

@@ -1635,7 +1635,7 @@ iterations of the loop.
 
    .. versionadded:: 3.13
 
-.. opcode:: FORMAT_SPEC
+.. opcode:: FORMAT_WITH_SPEC
 
    Formats the given value with the given format spec::